Lionel Legacy 4-6-6T Smoke Unit Help Needed

Well, the whistle smoke motor should not run all the time.  Obviously, if the motor is running, that could indeed cause smoke to leak out all the time as well.  It also indicates something is broken!  The whistle steam keeps the heater on at a lower setting all the time so when the whistle blows, you get immediate smoke.

I've had more than one of the older dual smoke units leak between units, usually when you replace the wick material.  You can't get the felt pad they put in the bottom of them to wick between the chambers but keep airflow from going between them, so when that's removed, you get smoke leakage.

What do you hear when you turn the sound off?

That doesn't look like the fan is running . That smoke is just wafting out of there.

What happens when you blow the whistle? Again, have the sound off so you can listen for the fan.

Additionally you have nothing coming out of the stack. Was this a new engine or used?

So is the best bet to replace the unit completely?  I think I have figured out how to get it out, seems like it is a bracket that holds it in, so I don't have to take the front of the boiler off to get to it.

@RickO posted:

What do you hear when you turn the sound off?

That doesn't look like the fan is running . That smoke is just wafting out of there.

What happens when you blow the whistle? Again, have the sound off so you can listen for the fan.

Additionally you have nothing coming out of the stack. Was this a new engine or used?

Ok I just went and tested these scenarios:

What do you hear when you turn the sound off? - just a fan running, you can hear it but not awful (maybe audible in the video)

What happens when you blow the whistle? Again, have the sound off so you can listen for the fan. - I hear a second fan kick on (thanks for the hint, dumb that I never turned the sounds off) then smoke comes out the whistle smoke hole per normal.

Additionally you have nothing coming out of the stack. Was this a new engine or used? - Used and interesting you mention nothing out of the stack.  When I just went to test your questions I turned it on and no smoke was coming out at all, I gave it a few seconds to warm up knowing I had run it today and it had plenty of fluid in it, but nothing happened.  Then I added just a few drops of smoke fluid and the result is what is in this video, started instantly to come out that way.  Is that an indication of an issue?

At the end of the video I tried to capture the smoke stack fan noise and then you can hear the whistle steam fan kick in.

For the most part. You appear to have normal operation in that video with the exception that the fans are excessively noise.

The whistle steam looks weak, but it's working. There are multiple reasons why it could be weak. Not enough fluid, or charred wicking just to name a couple.

These dual smoke units Lionel uses take alot of fluid . The fluid only goes into the stack resovior. Then the fluid bleeds over into the whistle steam resovior.

When an engine is new. I'll typically give it multiple fills of 10 drops at a time. I'll give it a day to wick over into the whistle steam bowl before I try it.

The wicking can char easily if the unit is set to high and doesn't have enough fluid. If it chars on the stack side. The fluid will not wick over to the whistle side.

Some times a drop of oil on the motor shaft under the fan impeller will quiet the motor. Otherwise you might just want to replace  them.

I think something like the wick being charred is the problem and I should just replace the unit.  I took two more videos here below, I started the engine and didn't add anymore fluid since I had just put some in.

The first is after one lap around the track and not blowing the whistle since I started the engine running, you can clearly see the smoke leaking out.  The second is the next lap with the whistle steam, you can see, when it blows it is quite good.

The engine is used so my assumption is the wick / unit was damaged by the previous owner. 

I agree with Rick, ….& I’ll add, …it appears your main stack smoke maybe leaching into the whistle side, and thus escaping. There’s no door way or valve, so it can just leach over, and out the whistle hole….Rick is correct, seems a bit weak on the whistle side. This could be caused by a gasket leak, and the majority of smoke volume & pressure for the whistle is being blown out the stack where it’s not noticeable because of the already good exhaust stream. I wouldn’t replace the unit, these are very rebuildable, and once you see how it all works, your personal tweaks can make it perform better than new.

Pat

Ok thanks, I'm going to try to pull the unit out tomorrow and look closely at it.  When I had the engine open today I wasn't confident on how to pull it out so I stopped playing with it.  I think I have that figured out now so I'll give it a shot tomorrow and report back.

@harmonyards posted:

I agree with Rick, ….& I’ll add, …it appears your main stack smoke maybe leaching into the whistle side, and thus escaping....

Pat

I have repaired a several dual smoke units. Some engines were brand new and showing the same problems that you have reported and as seen in the videos.  What Pat is stating is spot on.  What I found is a small amount of air is leaking from the main smoke chamber into the secondary chamber (whistle steam).  In three cases, the leak was from air going under the metal separating baffle.  There is a notch in this baffle to allow fluid to flow between the chambers and if the smoke wick packing is too loose, air will also flow under the baffle.  Lionel use to place a wick of sorts in this notch.  The last two repairs did not have this and the wick packing was two separate pieces, one on each side.  When I replaced the packing, I placed some wick material under the metal notch.  This still allows for the wicking of the fluid and greatly reduces air flow thus reducing the lofting steam from the whistle when no whistle is requested.

@DaveGG posted:

I have repaired a several dual smoke units. Some engines were brand new and showing the same problems that you have reported and as seen in the videos.  What Pat is stating is spot on.  What I found is a small amount of air is leaking from the main smoke chamber into the secondary chamber (whistle steam).  In three cases, the leak was from air going under the metal separating baffle.  There is a notch in this baffle to allow fluid to flow between the chambers and if the smoke wick packing is too loose, air will also flow under the baffle.  Lionel use to place a wick of sorts in this notch.  The last two repairs did not have this and the wick packing was two separate pieces, one on each side.  When I replaced the packing, I placed some wick material under the metal notch.  This still allows for the wicking of the fluid and greatly reduces air flow thus reducing the lofting steam from the whistle when no whistle is requested.

Thank you, this description is extremely helpful.  I'm hoping to have time today to take a closer look and see if what I see matches your description above.

When replacing the smoke wick packing, can you recommend or link where to get that material?

@ArtsModelTrains posted:

Thank you, this description is extremely helpful.  I'm hoping to have time today to take a closer look and see if what I see matches your description above.

When replacing the smoke wick packing, can you recommend or link where to get that material?

When I rebuild them, I like to use MTH’s smoke wick materiel. I find their materiel to be the easiest to work with, and since it’s sold basically in strands, I can cut it up with scissors to pack it how I see fit,……others may have different approaches, …..but me personally, I can’t stand the material Lionel currently uses, ….it seems to char almost instantly, no matter how damp you keep it,….

Pat

@ArtsModelTrains posted:

Thank you, this description is extremely helpful.  I'm hoping to have time today to take a closer look and see if what I see matches your description above.

When replacing the smoke wick packing, can you recommend or link where to get that material?

Here’s the wicking material I use, ….available at mthpartsandsales.com for small money, ……10 bucks worth would last a right good while for supplies….

Pat

I was able to take the locomotive apart today and get to the smoke unit and it appears that I found the issue.  The tube running to the Whistle Smoke appears to have melted and possibly developed a hole.

Then, once I got inside the unit it does appear to have a charred wick.  I added a picture of that below, I have never looked inside one of these, is that what a charred wick looks like? 

I was planning on replacing both the hose and the wick, does that sound like the right approach?

That fan impeller looks pretty bad as well!

While you have it open, I'd really soak the whistle side and give it a head start on having fluid.

That burned spot on that hose concerns me, ….that happened from something exterior, not interior……can you forensic science it and see what that tubing was laying against, and or near? …..need to cure that issue …….also, hard to tell from the picture, but does one of the impellers look to be melted? ….I could be wrong, won’t be the first time……

Pat

Something is going on with the impeller, and given the hose issue, I'd say the whistle smoke side has a problem.

yup agree, I just dug in there and that hole is on the side of the hose that sits right under the whistle smoke side of the unit.  Could the lack of fluid in the unit or on that side of the unit be what case the heat element to melt the impeller and the hose? 

Also, it's hard to see in these photos but the hose has some moisture in it and the unit has somewhere that hole it is the hose.  Could fluid have gone into the hose?

So does this mean more than just replacing the wick and the hose?  Does that impeller / motor need to be replaced too?  Are those available as parts vs buying a whole unit?

Here are some photos showing the hose right by the fan and the damage to both the fan and hose.

I had the impeller melt on my 4-8-4 Northern from 2019, the temperature sensors were soldered in too high and had the heater run at maximum power all the time. Check the temperature sensor height, it should be in line with the heater and also touching the batting. Also the distance between the heater and temperature sensor should be around a 1/4 inch.

These engines were in the same catalog as the 4-8-4 Northerns, so it's likely the smoke unit wasn't made quite right for the whistle steam.

Also you can use Tiki torch wicking to make new batting for smoke units, they're fiberglass. The only thing that needs to be done with Tiki torch wicks is to cut the wrapping down the middle and remove all the strands inside, you only want to use the strands inside inside the smoke unit. Length can be 2-2.5 what the length of the chamber is

Here's another interesting photo I took of inside the unit, I noticed that the whistle smoke side looks more discolored. You can even see the hole above the impeller is discolored.

I wonder if it has to do with the temperature sensor you mentioned. Is that the smaller piece sticking out from the board?

Everything is pretty much on par with the used one I bought. I believe the smoke unit design is poor. The divider can slide out and shows a notch. Thats because the only way to fill the unit(s) is throught the stack side and absorbs through the bottom of the stack to the whistle side. I feel like you can never get enough juice on the whistle side, even if you flood the smoke stack. The whistle side overheats and burns a hole in the tube, melts the impeller fans etc. Unfortunate but seems to be a common issue.

I haven't read through all the comments , but the thermistor  looks to far away from the resistor which can be the cause of the impeller, and hose burning up. I can also see some melted plastic in the smoke bowl .

Alex

@ArtsModelTrains posted:

Here's another interesting photo I took of inside the unit, I noticed that the whistle smoke side looks more discolored. You can even see the hole above the impeller is discolored.

I wonder if it has to do with the temperature sensor you mentioned. Is that the smaller piece sticking out from the board?

The red glass piece is the thermistor. The thing to note with it is that the closer it is, the cooler the heating element is. I've found a 1/4" gap between the 2 is just about perfect for smoke output without melting anything. Make sure the thermistor isn't touching the bowl or metal plate, as that will throw off the temperature reading.

I checked the temperature sensor and it is just about a quarter of an inch away from the element on both sides.

BUT I found something more interesting lol. Based on the comment above about melted plastic I took a closer look one of the blades of the impeller is completely melted off the gap next to the impeller is partially melted and then there is this giant melted plastic ball under the element! I'm guessing that is also a big part of the problem.

@ArtsModelTrains posted:

I checked the temperature sensor and it is just about a quarter of an inch away from the element on both sides.

BUT I found something more interesting lol. Based on the comment above about melted plastic I took a closer look one of the blades of the impeller is completely melted off the gap next to the impeller is partially melted and then there is this giant melted plastic ball under the element! I'm guessing that is also a big part of the problem.

Alex is spot on 100% correct, & he nailed your diagnosis, …..that thermistor is indeed too far away, ….it needs to be danger close to the element ( resistor ) …..1/16” gap preferred……I plumb forgot about that …..good catch Alex!!

Pat

As you noted, you have a couple of things to address.

Look at the metal divider.  Notice the discolored area.  I would move the resistor further away from the divider and closer to the thermistor (temperature sensor).

The unit got hot enough to melt the discharge tubing and impeller.  Not sure any amount of smoke fluid would have stopped this.  My guess is some hot vapors went out the intake port of the fan and melted the plastic tubing.  The inside of the plastic tubing was most likely already hot.  Not liking the design of the discharge tubing right on top of the fan intake port.  Once tubing was compromised, even if the fan was not damaged at this point, hot vapors were pulled into the fan intake (when whistle was running) and you had a cascade failure (vapor get hotter with the recycle flow) which took out the fan.

You'll have to see if the fan impeller is available individually.  I have noticed several fan impellers sizes are no longer available on the Lionel parts website.  You may be stuck purchasing an entire unit.

Biggest concern is you have to prevent the overheating.

I would recommend looking at the routing of the tubing.  Not sure anything can be done about this. Any obstruction to the intake port is not a good thing.  Lower air flow with lead to a higher discharge air/vapor (smoke) temperature.  I understand that the unit stays warm so vapors are seen quickly when whistle smoke is activated. Not sure if the heating unit receives more power once the whistle is activated. Again, restricting air flow is not a good thing with intake flow being very sensitive to restrictions.

Good luck on the repair.

Dave’s got it right too,….we’re all rebuilding this thing for you Art, and we haven’t touched the first screw!…..😉

Pat

Thanks for all the help! I'm going to put it aside for now and figure out how to fix it after Christmas.

Runs great so I'm OK if it takes some time tk get it smoking right.

Ok, so I decided to go ahead and just replace the whole smoke unit in this engine to avoid future issues.  I was able to get the parts from Lionel (smoke unit and tube for whistle steam) but of course I made a rookie mistake.  I forgot to fully disassemble the smoke unit and I didn't realize the smoke funnel was also damaged by this smoke unit.  So, after starting work tonight, I had to pause and order another piece from Lionel.

Don’t assume ( hopefully you know the definition of assume) the new unit is 100% correct. Most all of us open up even the new unit and move the thermistors closer to the heater elements…..this will give you better longevity of the unit.

Pat

yup, was planning on that based on the feedback everyone gave me here.  I'll open that unit and make sure it is 1/16th apart as @harmonyards mentioned above. 

I also heard from someone that these 4-6-6T's had a code issue that caused the unit to get too hot and the only true fix is for Lionel to fix the code?  Does that sound right?

@ArtsModelTrains posted:

yup, was planning on that based on the feedback everyone gave me here.  I'll open that unit and make sure it is 1/16th apart as @harmonyards mentioned above.

I also heard from someone that these 4-6-6T's had a code issue that caused the unit to get too hot and the only true fix is for Lionel to fix the code?  Does that sound right?

I haven’t heard about these being affected, but I have learned from another tech about a different model having that coding issue. So, that wouldn’t surprise me if it was.

Pat

I reached to Lionel to see what they say and I'll do like you said and check the new smoke unit.  I guess that is the best I can do and cross my figures I don't have further issues.

I have to wonder if someone replaced the smoke resistor with the wrong Ohm's. And caused that side of the unit to overheat and burn. Maybe it calls for a 6 or 8 Ohm and someone put a 27 Ohm in it because it looked the same.

@Secarider posted:

I have to wonder if someone replaced the smoke resistor with the wrong Ohm's. And caused that side of the unit to overheat and burn. Maybe it calls for a 6 or 8 Ohm and someone put a 27 Ohm in it because it looked the same.

You’re going in the wrong direction buddy, ….with a 27 it wouldn’t even smoke at all,…..more than likely, 2 things possibly at play here, either the thermistors aren’t doing an effective job, or the board’s coding characteristics are off, causing more power to reach the resistor, …..

Pat

All the Legacy units with the RCMC or RCMD boards should be using an 8 ohm smoke resistor.  Changing that would result in either much less smoke or likely cooking the board.

Thanks for all the help, last night I was finally able to work on the engine after getting all the parts from Lionel. I replaced the smoke unit, smoke funnel and tube for whistle smoke. I opened the new smoke unit and squeezed the heat element and thermistor close to each other as mentioned above, about 1/16. The as John mentioned above I soaked the unit with fluid. Seems to work great, almost too much! But I'm so worried it will burn up again, there is a small smell with the new unit, I'm assuming at this point that is just breaking in, fingers crossed. I have loaded it with fluid too which I assume might be contributing to the smell.